Multielement synergetic effect of NiFeO and h-BN for improving the dehydrogenation properties of LiAlH

Effective hydrogen storage is one of the main unresolved challenges towards deploying the so-called hydrogen economy. LiAlH 4 is considered a promising candidate for hydrogen storage due to its high hydrogen storage capacity and the relative abundance of aluminum. However, it also has the disadvantages of slow kinetics, high dehydrogenation temperature and poor reversibility. To improve these shortcomings of LiAlH 4 , we made a composite material by incorporating hexagonal boron nitride supported NiFe 2 O 4 (NiFe 2 O 4 @h-BN) into it. We then studied the effect of NiFe 2 O 4 @h-BN composites on the dehydrogenation and rehydrogenation behaviors of LiAlH 4 using thermogravimetric analysis, mass spectrometry and the Sieverts-type pressure composition temperature. The results showed that the onset decomposition temperature of LiAlH 4 doped with 7 wt% NiFe 2 O 4 @h-BN is 77.1 °C with 6.74 wt% hydrogen released. In addition, under 30 bar pressure hydrogen and at 300 °C constant temperature, the LiAlH 4 doped with 7 wt% NiFe 2 O 4 @h-BN after dehydrogenation absorbed nearly 0.6 wt% of hydrogen in 11 hours. At the same time, Al 4 Ni 3 and LiFeO 2 were found in LiAlH 4 doped with NiFe 2 O 4 @h-BN after ball milling, and Al 1.1 Ni 0.9 was obtained during heating. NiFe 2 O 4 @h-BN composites significantly improved the dehydrogenation and rehydrogenation properties of LiAlH 4 . The Al 4 Ni 3 and LiFeO 2 found in doped LiAlH 4 , and Al 1.1 Ni 0.9 in the process of heating, improved the dehydrogenation properties of LiAlH 4 .